Temperature inversions and their types. Inversion. Myths and more. See the meaning of Temperature Inversion in other dictionaries

With increasing altitude. Most often this applies to temperature inversion, that is, to an increase in temperature with height in a certain layer of the atmosphere instead of the usual decrease.

There are two types of inversion:

• surface temperature inversions starting directly from the earth's surface (the thickness of the inversion layer is tens of meters)
• temperature inversion in the free atmosphere (the thickness of the inversion layer reaches hundreds of meters)

Temperature inversion prevents vertical air movement and contributes to the formation of haze, fog, smog, clouds, and mirages. Inversion strongly depends on local terrain features. The temperature increase in the inversion layer ranges from tenths of a degree to 15-20°C or more. Surface temperature inversions are most powerful in Eastern Siberia and Antarctica in winter.

Normal atmospheric conditions

Typically, in the lower atmosphere (troposphere), the air near the Earth's surface is warmer than the air above because the atmosphere is primarily heated by solar radiation through the Earth's surface. As altitude changes, the air temperature decreases, the average rate of decrease is 1 °C for every 160 m.

Causes and mechanisms of inversion

Under certain conditions, the normal vertical temperature gradient changes in such a way that cooler air ends up near the Earth's surface. This can happen, for example, when a warm, less dense air mass moves over a cold, more dense layer. This type of inversion occurs near warm fronts, as well as in areas of oceanic upwelling, such as off the coast of California. With sufficient moisture in the cooler layer, fog formation under the inversion “lid” is typical.

Inversion of descent

A temperature inversion can occur in the free atmosphere when a broad layer of air sinks and is heated by adiabatic compression, which is usually associated with subtropical high pressure areas. Turbulence can gradually lift the inversion layer to a greater height and “puncture” it, resulting in the formation of thunderstorms and even (under certain circumstances) tropical cyclones.

Consequences of temperature inversion

When the normal convection process ceases, the lower layer of the atmosphere becomes polluted. This causes problems in cities with large emissions. Inversion effects often occur in large cities such as Mumbai (India), Los Angeles (USA), Mexico City (Mexico), Sao Paulo (Brazil), Santiago (Chile) and Tehran (Iran). Small cities such as Oslo (Norway) and Salt Lake City (USA), located in valleys of hills and mountains, are also influenced by the blocking inversion layer. With a strong inversion, air pollution can cause respiratory diseases. The Great Smog of 1952 in London is one of the most serious such events - more than 10 thousand people died because of it.

Links

• Temperature inversion- article from the Great Soviet Encyclopedia
• Khrgian A. Kh., Atmospheric Physics, M., 1969.

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See what “Temperature Inversion” is in other dictionaries:

A phenomenon observed when temperature increases with altitude instead of decreasing, that is, when there is a negative temperature gradient in the atmosphere. Samoilov K.I. Marine dictionary. M.L.: State Naval... ... Naval Dictionary

temperature inversion- An increase in temperature with height in a certain layer of the atmosphere instead of its usual decrease. Syn.: temperature inversion… Dictionary of Geography

Big Encyclopedic Dictionary

temperature inversion- 3.37 temperature inversion: An increase in air temperature with height instead of the usual decrease in a certain layer of the atmosphere. Temperature inversions occur both in the ground layer of air, starting from the soil surface (ground inversion), and in... ... Dictionary-reference book of terms of normative and technical documentation

An increase in air temperature with height in a certain layer of the atmosphere instead of the usual decrease. There are surface temperature inversions, starting directly from the earth's surface, and temperature inversions in the free atmosphere; the first ones more often... ... encyclopedic Dictionary

temperature inversion- temperatūros apgrąža statusas T sritis radioelektronika atitikmenys: engl. temperature inversion vok. Temperatururmkehr, f rus. temperature inversion, f pranc. inversion de temperature, f… Radioelektronikos terminų žodynas

An increase in air temperature with height in a certain layer of the atmosphere instead of the usual decrease. A distinction is made between surface irradiation, starting directly from the earth's surface, and irradiation in the free atmosphere; the first are most often associated with air cooling... ... Natural science. encyclopedic Dictionary

This term has other meanings, see Inversion. Rising smoke is contained by an overlying layer of warmer air (Sho ... Wikipedia

- (lat.). Transformation in general and especially transformation. sugars into glucose and fructose. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. INVERSION [lat. inversio inversion, rearrangement] 1) linguistic. changing the usual order... ... Dictionary of foreign words of the Russian language

One of the fundamental concepts of physics and statistical mechanics, used to describe the principles of operation of lasers. Contents 1 Boltzmann distribution and thermodynamic equilibrium ... Wikipedia

Paragliders associate a lot of impressions and memories with the concept of “inversion”. Usually they talk about this phenomenon with regret, something like “again, a low inversion prevented me from flying a good route” or “I ran into an inversion and could not gain more.” Let's look at this phenomenon, is it so bad? And with the usual mistakes that paragliders make when talking about “inversion”.

So let's start with Wikipedia:

Inversion in meteorology - means the anomalous nature of changes in any parameter in the atmosphere with increasing altitude. Most often this applies to temperature inversion, that is, to an increase in temperature with height in a certain layer of the atmosphere instead of the usual decrease.

So it turns out that when we talk about “inversion”, we are talking specifically about temperature inversion. That is, about an increase in temperature with height in a certain layer of air.– It is very important to firmly understand this point, because speaking about the state of the atmosphere, we can highlight that for the lower part of the atmosphere (before the tropopause):

• Normal condition– when the air temperature increases with altitude – decreases. For example, the average rate of temperature decrease with height for a standard atmosphere is accepted by ICAO as 6.49 degrees K per km.

• Not normal condition remains constant(isothermia)

• Also not a normal state– when the temperature increases with altitude increases (temperature inversion)

The presence of isothermia or real inversion in some layer of air means that the atmospheric gradient here is zero or even negative, and this clearly indicates the STABILITY of the atmosphere ().

A freely rising volume of air, entering such a layer, very quickly loses its difference in temperature between it and the environment. (The air rising is cooled along a dry or moist adiabatic gradient, and the air surrounding it does not change temperature or even heats up. That temperature difference, which was the reason for the excess of Archimedes' force over the force of gravity is quickly leveled out and the movement stops).

Let's give an example, suppose we have a certain volume of air that has overheated at the surface of the earth, relative to the air surrounding it, by 3 degrees K. This volume of air, breaking away from the ground, generates a thermal bubble (thermal). At the initial stage, its temperature is 3 degrees higher, and therefore the density for the same volume, compared to the air around it, is lower. Consequently, the force of Archimedes will exceed the force of gravity, and the air will begin to move upward with acceleration (float). Floating upward, the atmospheric pressure will fall all the time, the floating volume will expand, and as it expands it will cool according to the dry adiabatic law (air mixing is usually neglected in large volumes).

How long will it take to float? - depends on how quickly the environment around it cools at altitude. If the law of change in the cooling of the environment is the same as the dry adiabatic law, then the initial “overheating relative to the environment” will be maintained all the time, and our rising bubble will accelerate all the time (the friction force will increase with speed, and at significant speeds it can no longer be neglected , the acceleration will decrease).

But such conditions are extremely rare; most often we have an atmospheric gradient in the region of 6.5 – 9 degrees K per km. Let's take 8 degrees K per km as an example.

The difference between the atmospheric gradient and dry adiabatic = 10-8 = 2 degrees K per km, then at an altitude of 1 km from the surface, from the initial overheating of 3 degrees, only 1 remained. (our bubble cooled by 9.8 = 10 degrees, and the surrounding air by 8). Another 500m of ascent and the temperatures will become equal. That is, at an altitude of 1.5 km, the temperature of the bubble and the temperature of the surrounding air will be the same, the Archimedes force and the force of gravity will be balanced. What will happen to the bubble? In all paragliding books, they write that it will remain at this level. Yes, ultimately, theoretically, this is exactly what will happen. But the dynamics of the process are also important for us flying.

The bubble will not hang at a new, equilibrium level immediately. And if there weren’t those phenomena that are neglected when describing the rise of a bubble (friction force, mixing with the surrounding air, heat exchange with the surrounding air), it would never have frozen :).

At first, “by inertia” it will jump above the equilibrium level (it was accelerating all the time it was rising and already has a decent speed, and therefore a reserve of kinetic energy. Rising above this level (1.5 km), the gradient will work in the opposite direction, then there is our volume of air will cool faster than the surrounding one, the force of gravity will exceed the force of Archimedes, and the resulting force will act downwards, braking (together with the friction force) its movement. At some height, their action will completely stop our bubble and it will begin downward movement. If we completely neglect the friction force and assume that the air does not mix with the surrounding air and does not exchange energy, then it would fluctuate up and down from 0 to 3000 m. But in reality this, of course, does not happen. Friction force, heat exchange and mixing - there are also fluctuations fade quickly and are limited especially quickly by layers with different gradients.

Let's now consider the same example, only with an inversion layer, a gradient in -5 degrees K per km (remember that in meteorology the gradient is with the opposite sign), at an altitude of 750m it is 300m thick.

Then in the first 750m our bubble will lose 1.5 degrees of overheating (10-8 = 2 degrees K per km. 2*0.75 = 1.5 degrees), rising further it will continue to cool by 1 degree for every 100m, and starting from a height of 750m , the surrounding air only increases its temperature. This means the difference between the gradients. 10–5=15 degrees K per km, or 1.5 degrees per 100m. And after the next 100m (at an altitude of 850 meters), the temperature of the bubble will be equal to the environment.

This means that the inversion layer with a gradient of -5 degrees K per km quickly stopped the bubble. (It will also quickly extinguish the inertia of the bubble, ideally after 200m, but in fact, taking into account friction, mixing and heat transfer, much earlier).

We see that the inversion layer limits the bubble oscillations (if we neglect friction, mixing and heat transfer) from the range of 0-3000m to the range of 0-1050m.

Is inversion really that bad? If it's at a low altitude and slows down our thermals, that's bad. If it is at a sufficiently high altitude and protects against the rise of air into instability zones in which condensation occurs, and where the moisture-adiabatic gradient is less than atmospheric, then inversion is good.

What causes temperature inversion?

After all, strictly speaking, for the thermodynamic equilibrium of the atmosphere to the level of the tropopause, this is not a normal state.

There are 2 types of inversion according to the place of manifestation:

• ground level (one that starts from the surface of the earth)
• inversion at height (some layer at height)

And we can distinguish 4 types of inversion, according to the types of its occurrence. We can easily encounter all of them in everyday life and on flights:

• ground-level radiation cooling
• leak inversion
• advective transport inversion
• subsidence inversion

WITH surface inversion It’s simple, it’s also called radiation cooling inversion or night inversion. The surface of the earth, with the weakening of heat from the sun, quickly cools (including due to infrared radiation). The cooled surface also cools the adjacent layer of air. Since air does not tolerate heat well, above a certain altitude this cooling is no longer felt.

Surface inversion

The thickness of the layer, the intensity of its supercooling depends on:

• duration of cooling, the longer the night, the more the surface and the adjacent layer of air cools. In autumn and winter, surface inversions are thicker and have a more pronounced gradient.
• cooling rate, for example, if there is cloudiness, then part of the infrared radiation with which heat escapes is reflected back to the ground, and the cooling intensity is noticeably reduced (cloudy nights are warm).
• The heat capacity of the underlying surface, which has a large heat capacity and has accumulated heat during the day, takes longer to cool and cools the air less (for example, warm bodies of water).
• the presence of wind near the ground, the wind mixes the air and it cools more intensely, the inversion layer (thickness) is noticeably larger.

Leak inversion- occurs when cold air flows from the slopes into the valley, displacing warmer air upward. Air can flow both from cooled slopes at night and during the day, for example from glaciers.

Leak inversion

Inversion of advective transport occurs during horizontal air transfer. For example, warm air masses on cold surfaces. Or just different air masses. A striking example is atmospheric fronts; an inversion will be observed at the front’s border. Another example is the advection of warm (at night) air from the water surface onto cold land. In autumn, such advection is often visualized by fogs. (that’s what they’re called, advective fogs, when moist warm air from water is transferred to cold land, or to colder water, etc.)

Occurs when external forces force some layer of air to fall down. As the air descends, it will compress (as atmospheric pressure increases) and heat up adiabatically, and it may turn out that the underlying layers have lower temperatures - an inversion will occur. This process can occur under different conditions and scales; such an inversion occurs, for example, when air settles in anticyclones, when air descends in a mountain-valley circulation, between a cloud with precipitation and the surrounding air nearby, or, for example, during a foehn. For its occurrence, a constant external influence is needed that carries out the transfer and lowering of air.

Let us now return to the myths about inversion.

Very often, paragliders talk about inversion where there is none. This is due to the fact that we are accustomed to calling any layer that noticeably slows down and delays the vertical movement of air inversion although this is not so. Just a layer with a small gradient, or isotherm, also quickly blocks the movement of air, but is not a true inversion.

The second point arose due to the fact that in books and illustrations, for clarity, they usually draw atmospheric gradients or an aerological diagram in RECTANGULAR COORDINATE SYSTEMS (RAC), where isotherms (lines of constant temperatures) are directed from bottom to top perpendicular to isobars (or lines of equal height). In such figures, inversion is any section of the stratification curve tilted to the RIGHT from vertical from bottom to top. The inversion in such coordinates is easily visible.

An example from D. Pegan’s book “Understanding the Sky.”

In practice, most people use it, for example, from the site meteo.paraplan.ru and here already, the isotherms themselves are inclined to the right, so in order to see the inversion, you need to compare the STEENness of the slope of the stratification curve with the isotherm! And doing this by eye with a quick glance is much more difficult than with a diagram in the ADP. Look at the chart below, there is a small surface inversion visible near the ground. In the 400m layer the temperature increased slightly (at an altitude of 600 meters it is about a degree warmer than at the ground) the gradient is about -2.5 degrees K per km. And at the top, NOT an inversion, but just a very small gradient, about +3.5 degrees K per km.

Inversion and Non-inversion

Due to the fact that not any tilt to the right will be an inversion on the ADC, pilots often use this word in the wrong place, which irritates true meteorologists :)

At the same time, calculated, model aerological diagrams may not predict thin inversion layers, since they average the temperature over the layer, instead of taking into account 2 layers, an inversion layer with a thickness of, for example, 100 m with a temperature difference at the lower and upper boundaries of -1 degree, an adjacent layer 900 meters with a temperature difference of +8 degrees. they will simply draw a thicker layer, 1 km - with an average gradient of 7 degrees per kilometer. While in reality there will be several different layers.

For example, as in the full-scale diagram (ADP) below. It also shows a surface inversion layer 200 m thick + an isothermal layer. And a thin inversion layer at an altitude of 2045m, and an isothermal layer at an altitude of 3120m. These thin layers are not calculated by the model, but in fact they have a strong influence on thermals.

Full-scale ADP from a balloon

Summary.

Not every part of the stratification curve inclined to the right on the ADC is an inversion, be careful! The real inversion can only be seen on an aerological diagram taken from actual atmospheric sounding data. On “model” diagrams, they may not be calculated, but only taken into account in reducing the gradient on some layer. However, in this case, their existence can be guessed if we take into account the possible factors for the occurrence of inversions.

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Just as in soil or water, heating and cooling are transferred from the surface to depth, so in air, heating and cooling are transferred from the lower layer to higher layers. Consequently, daily temperature fluctuations should be observed not only at the earth's surface, but also in high layers of the atmosphere. At the same time, just as in soil and water the daily temperature fluctuation decreases and lags with depth, in the atmosphere it should decrease and lag with altitude.

Non-radiative heat transfer in the atmosphere occurs, as in water, mainly through turbulent thermal conductivity, i.e., when air is mixed. But air is more mobile than water, and its turbulent thermal conductivity is much greater. As a result, daily temperature fluctuations in the atmosphere extend to a thicker layer than daily fluctuations in the ocean.

At an altitude of 300 m above land, the amplitude of the daily temperature variation is about 50% of the amplitude at the earth's surface, and the extreme temperature values ​​occur 1.5-2 hours later. At an altitude of 1 km, the daily temperature amplitude over land is 1--2°, at an altitude of 2-5 km it is 0.5--1°, and the daily maximum shifts to the evening. Over the sea, the daily temperature amplitude increases slightly with altitude in the lower kilometers, but still remains small.

Small daily temperature variations are found even in the upper troposphere and lower stratosphere. But there they are determined by the processes of absorption and emission of radiation by the air, and not by the influences of the earth's surface.

In the mountains, where the influence of the underlying surface is greater than at corresponding altitudes in the free atmosphere, the daily amplitude decreases more slowly with altitude. On individual mountain peaks, at altitudes of 3000 m and more, the daily amplitude can still be 3-4°. On high, extensive plateaus, the daily amplitude of air temperature is of the same order as in the lowlands: the absorbed radiation and effective radiation here are large, as is the surface of contact between the air and the soil. The daily amplitude of air temperature at Murghab station in the Pamirs is on average 15.5°, while in Tashkent it is 12°.

Temperature inversion

In previous paragraphs we have repeatedly mentioned temperature inversions. Now let us dwell on them in a little more detail, since important features in the state of the atmosphere are associated with them.

A decrease in temperature with height can be considered the normal state of affairs for the troposphere, and temperature inversions can be considered deviations from the normal state. True, temperature inversions in the troposphere are a frequent, almost everyday phenomenon. But they capture air layers that are quite thin compared to the entire thickness of the troposphere.

Temperature inversion can be characterized by the height at which it is observed, the thickness of the layer in which there is an increase in temperature with height, and the temperature difference at the upper and lower boundaries of the inversion layer - a temperature jump. As a transition case between the normal temperature drop with height and inversion, the phenomenon of vertical isothermia is also observed, when the temperature in a certain layer does not change with height.

By height, all tropospheric inversions can be divided into surface inversions and inversions in the free atmosphere.

Surface inversion starts from the underlying surface itself (soil, snow or ice). Over open water, such inversions are rarely observed and are not so significant. The underlying surface has the lowest temperature; it grows with height, and this growth can extend over a layer of several tens or even hundreds of meters. The inversion is then replaced by a normal decrease in temperature with height.

Inversion in a free atmosphere observed in a certain layer of air lying at a certain height above the earth's surface (Fig. 5.20). The base of the inversion can be at any level in the troposphere; however, the most common inversions are within the lower 2 km(if we don’t talk about inversions at the tropopause, which are actually no longer tropospheric). The thickness of the inversion layer can also be very different - from a few tens to many hundreds of meters. Finally, the temperature jump at the inversion, i.e. the temperature difference at the upper and lower boundaries of the inversion layer, can vary from 1° or less to 10-15° or more.

Frost

The phenomenon of frost, which is important in practical terms, is associated with both the daily variation of temperature and its non-periodic decreases, and both of these reasons usually act together.

Frosts are called drops in air temperature at night to zero degrees or below at a time when average daily temperatures are already above zero, i.e. in spring and autumn.

Spring and autumn frosts can have the most unfavorable consequences for garden and vegetable crops. It is not necessary for the temperature to drop below zero in the weather booth. Here, at a height of 2 m, it may remain slightly above zero; but in the lowest air layer, at the same time, it drops to zero and below, and garden or berry crops are damaged. It also happens that the air temperature, even at a small altitude above the soil, remains above zero, but the soil itself or the plants on it are cooled by radiation to a negative temperature and frost appears on them. This phenomenon is called soil frost and can also kill young plants.

Frosts most often occur when a sufficiently cold air mass, such as arctic air, enters an area. The temperature in the lower layers of this mass during the day is still above zero. At night, the daily air temperature drops below zero, i.e. frost is observed.

For freezing, a clear and quiet night is needed, when the effective radiation from the soil surface is high and turbulence is low and the air cooled from the soil is not transported to higher layers, but undergoes long-term cooling. Such clear and calm weather is usually observed in the inner parts of areas of high atmospheric pressure, anticyclones.

Strong nighttime cooling of the air near the earth's surface leads to the fact that the temperature rises with altitude. In other words, when freezing occurs, a surface temperature inversion occurs.

Frosts occur more often in lowlands than in elevated places or on slopes, since in concave landforms the nighttime temperature drop is enhanced. In low places, cold air stagnates more and takes longer to cool.

Therefore, frost often affects orchards, orchards or vineyards in low areas, while on hillsides they remain undamaged.

The last spring frosts are observed in the central regions of the European CIS at the end of May - beginning of June, and already at the beginning of September the first autumn frosts are possible (maps VII, VIII).

Currently, quite effective means have been developed to protect gardens and vegetable gardens from night frosts. The vegetable garden or garden is covered with a smoke screen, which reduces the effective radiation and reduces the nighttime temperature drop. Various types of heating pads can be used to warm up the lower layers of air accumulated in the ground layer. Areas with garden or vegetable crops can be covered at night with a special film, straw or plastic canopies can be placed over them, which also reduce the effective radiation from the soil and plants, etc. All such measures should be taken when the temperature is quite low in the evening and, According to the weather forecast, it will be a clear and quiet night.

The temperature gradient of the atmosphere can vary widely. On average, it is 0.6°/100 m. But in a tropical desert near the surface of the earth it can reach 20°/100 m. With temperature inversion, the temperature increases with height and the temperature gradient becomes negative, i.e. it can be equal to, for example , -0.6°/100 m. If the air temperature is the same at all altitudes, then the temperature gradient is zero. In this case, the atmosphere is said to be isothermal.[...]

Temperature inversions determine the reverse arrangement of vertical soil zones in many mountain systems of continental regions. Thus, in Eastern Siberia, at the foot and in the lower parts of the slopes of some mountains there are inversion tundras, then there are mountain taiga forests and higher again mountain tundras. Inversion tundras cool only in certain seasons, and during the rest of the year they are much warmer than the “upper” tundras and are used in agriculture.[...]

Temperature inversion manifests itself in an increase in air temperature with height in a certain layer of the atmosphere (usually in the range of 300-400 m from the Earth's surface) instead of the usual decrease. As a result, the circulation of atmospheric air is sharply disrupted, smoke and pollutants cannot rise upward and do not dissipate. Fogs often occur. Concentrations of sulfur oxides, suspended dust, and carbon monoxide reach levels dangerous to human health, leading to circulatory and respiratory disorders, and often to death. In 1952, in London, more than four thousand people died from smog from December 3 to December 9, and up to ten thousand people became seriously ill. At the end of 1962, in the Ruhr (Germany), smog killed 156 people in three days. Only the wind can dispel smog, and reducing the emissions of pollutants can smooth out a smog-dangerous situation.[...]

Temperature inversions are associated with cases of mass poisoning of the population during periods of toxic fog (the Manet River valley in Belgium, more than once in London, Los Angeles, etc.).[...]

Sometimes temperature inversions spread over large areas of the earth's surface. The area of ​​their distribution usually coincides with the area of ​​distribution of anticyclones, which arise in zones of high barometric (Pressure.[...]

Synonym: temperature inversion. FRICTION INVERSION. See turbulent inversion.[...]

Under the influence of cold winters and temperature inversions, soils freeze deeply in winter and slowly warm up in spring. For this reason, microbiological processes are weak, and despite the high humus content in the soil, it is necessary to introduce increased rates of organic fertilizers (manure, peat and composts) and mineral fertilizers that are easily accessible to plants.[...]

Two other types of local inversions are possible. One of them is related to the sea breeze mentioned above. Warming of the morning air over land causes cooler air to flow landward from the ocean or large enough lake. As a result, warmer air rises and cooler air takes its place, creating inversion conditions. Inversion conditions are also created when a warm front passes over a large continental land area. A warm front often tends to "crush" denser, cooler air ahead of it, thereby creating a local temperature inversion. The passage of a cold front, in front of which there is an area of ​​warm air, leads to the same situation.[...]

Temperature inversion associated with vertical air movements can lead to the same consequences.[...]

The fan-shaped shape of the strings occurs during a temperature inversion. Its shape resembles a meandering river, which gradually widens with distance from the pipe.[...]

In the small American city of Donora, such a temperature inversion caused illness in about 6,000 people (42.7% of the total population), with some (10%) showing symptoms indicating the need for hospitalization of these people. Sometimes the consequences of a long-term temperature inversion can be compared to an epidemic: in London, 4,000 people died during one of these long-term inversions.[...]

A fan-shaped jet (Fig. 3.2, c, d) is formed during temperature inversion or at a temperature gradient close to isothermal, which characterizes very weak vertical mixing. The formation of a fan-shaped jet is favored by weak winds, clear skies and snow cover. This jet is most often observed at night.[...]

During unfavorable meteorological situations, such as temperature inversion, high air humidity and precipitation, the accumulation of pollution can occur especially intensively. Typically, in the surface layer, the air temperature decreases with height, and vertical mixing of the atmosphere occurs, reducing the concentration of pollution in the surface layer. However, under certain meteorological conditions (for example, during intense cooling of the earth's surface at night), a so-called temperature inversion occurs, i.e., the temperature in the surface layer changes to the opposite direction; with increasing altitude, the temperature increases. Typically, this condition lasts a short time, but in some cases, a temperature inversion can be observed for several days. During a temperature inversion, the air near the earth's surface appears to be enclosed in a limited volume, and very high concentrations of pollution can occur near the earth's surface, contributing to increased contamination of insulators.[...]

Burnazyan A.I. et al. Pollution of the surface layer of the atmosphere during temperature inversions.[...]

DUST HORIZON. The upper boundary of the dust (or smoke) layer underlying the temperature inversion. When observed from a height, the impression of a horizon is created.[...]

Under some unfavorable meteorological conditions (low wind, temperature inversion), the release of harmful substances into the atmosphere leads to mass poisoning. An example of mass poisoning of the population are the disasters in the Meuse River valley (Belgium, 1930), in the city of Donora (Pennsylvania, USA, 1948). In London, mass poisoning of the population during catastrophic air pollution was observed repeatedly - in 1948, 1952, 1956, 1957, 1962; As a result of these events, several thousand people died, many were seriously poisoned.[...]

In areas with anticyclonic weather and in the presence of significant inversions, the maximum accumulation of impurities is observed in valleys and basins in the zone of “cold lakes,” i.e., at a level of 200-300 m from their bottom, therefore, when forming the functional-planning structure of a city settlement, it is necessary In addition to the wind rose, take into account the rose of temperature inversions and their duration. The settlement zone is located on the slopes above the “cold lakes”, and the industrial zone is located lower in relief in relation to the residential area; streets and open retail spaces are oriented in the direction of prevailing winds to enhance ventilation. When forming an industrial zone at the foot of hills and mountains, planning methods are used to organize the passage of cold air masses flowing into depressions, using protective zones, streets, driveways, etc.[...]

In the depressions of cities (for example, Los Angeles, Kemerovo, Alma-Ata, Yerevan), a temperature inversion is observed, as a result of which natural mixing of air masses does not occur, and harmful substances accumulate in it. The problem of photochemical smog also exists in other large cities where sunny weather prevails (Tokyo, Sydney, Mexico City, Buenos Aires, etc.).[...]

Old-timers of New York know well what poisonous air is. In 1935, more than 200 people died in a few days of temperature inversion, in 1963 - more than 400, and in 1966 - about 200 people.[...]

Los Angeles (summer, photochemical) smog occurs in the summer also in the absence of wind and temperature inversion, but always in sunny weather. It is formed when solar radiation affects nitrogen oxides and hydrocarbons entering the air as part of vehicle exhaust gases and industrial emissions. As a result, highly toxic pollutants are formed - photooxidants, consisting of ozone, organic peroxides, hydrogen peroxide, aldehydes, etc. [...]

Products of incomplete combustion of fuel, which react with airborne fog during periods of temperature inversion, are the cause of the formation of smog, which has claimed many lives in the past.[...]

The acute effect of atmospheric pollution is provoked by a sharp change in weather conditions in a given territory (temperature inversion, calm, fog, strong steady wind from the industrial zone), as well as accidents at industrial enterprises of the city or at wastewater treatment plants, as a result of which the concentration of pollution in the atmospheric air of residential areas areas increases significantly, often exceeding permissible levels by tens of times. A particularly difficult situation arises in cases where both of these events occur simultaneously.[...]

In a number of cities, atmospheric emissions are so significant that in weather unfavorable for self-purification of the atmosphere (calm air, temperature inversion, in which smoke spreads to the ground, anticyclonic weather with fog), the concentration of pollutants in the surface air reaches a critical value, at which an acutely expressed reaction of the body to harmful atmospheric emissions. In this case, two situations are distinguished (dense fog mixed with smoke) of the London type and photochemical fog (Los Angeles). [...]

London type; smog occurs in winter in large industrial cities under unfavorable weather conditions (lack of wind and temperature inversion).[...]

London (winter) smog is formed in winter in large industrial centers under unfavorable weather conditions: lack of wind and temperature inversion. Temperature inversion manifests itself in an increase in air temperature with height (in a layer of 300-400 m) instead of the usual decrease.[...]

Atmospheric air pollution negatively affects public health and sanitary living conditions. When there is no wind, fog and temperature inversions, when the dispersion of emissions is difficult, the concentration of impurities in the air increases, especially sulfur dioxide and photooxidants, which has an acute effect on people, causing lacrimation, conjunctivitis, cough, bronchitis, as well as exacerbation of diseases, chronic obstructive pulmonary diseases , cardiovascular diseases.[ ...]

The accumulation of photochemical reaction products in the atmospheric air as a result of unfavorable meteorological conditions (lack of wind, temperature inversions) leads to a situation called photochemical smog, or Los Angeles-type smog. The main symptoms of such smog are irritation of the mucous membranes of the eyes and nasopharynx in humans, decreased visibility, a characteristic unpleasant odor, as well as the death of vegetation and damage to rubber products. At the same time, the oxidizing capacity of air significantly increases due to the presence of oxidizing agents in it, primarily ozone and some others. [...]

Areas with a predominance of weak winds or calm conditions are especially unfavorable for the dispersion of harmful substances in the air. Under these conditions, temperature inversions occur, during which there is an excessive accumulation of harmful substances in the atmosphere. An example of such an unfavorable location is Los Angeles, sandwiched between a mountain range that weakens the wind and prevents the flow of polluted urban air, and the Pacific Ocean. In this city, temperature inversions occur on average 270 times a year, and 60 of them are accompanied by very high concentrations of harmful substances in the air.[...]

Here, per capita, a much larger amount of petroleum products, including motor gasoline, is consumed per capita than anywhere else. At the same time, almost no coal is used. The air is polluted mainly by hydrocarbons and other products of petroleum combustion, as well as products from the burning of household and garden waste by private homeowners. Recently, measures have been taken to centralize the collection and disposal of household waste. Legislation prohibits the release into the atmosphere of smoke with a density of 2 or more units on the Ringelmann scale for more than 3 minutes per hour. Sulfur compounds may be released into the atmosphere in concentrations not exceeding 0.2% by volume. This emission limitation is not too stringent, since it fully allows the use of oil with a sulfur content of 3% in power plants. Regarding dust emissions, this county's ordinance provides: a scale that varies depending on the total amount of fuel consumed. The maximum emission should not exceed 18 kg per hour. Such a restriction would be impractical in many areas, but in Los Angeles County almost no coal is used and there are several plants that emit large amounts of dust into the atmosphere.[...]

The ability of the earth's surface to absorb or emit heat affects the vertical distribution of temperature in the surface layer of the atmosphere and leads to temperature inversion (deviation from adiabaticity). An increase in air temperature with altitude means that harmful emissions cannot rise above a certain ceiling. Under inversion conditions, turbulent exchange is weakened and conditions for the dispersion of harmful emissions in the surface layer of the atmosphere worsen. For the surface inversion, the repeatability of the heights of the upper boundary is of particular importance; for the elevated inversion, the repeatability of the lower boundary is of particular importance.[...]

In the Soviet Union, there was also a case of poisoning of the population of an industrial city with sulfur dioxide in winter as a result of the formation of a powerful layer of temperature inversion near the ground, which contributed to the pressing of a jet of flue gases to the ground. [...]

It is necessary to avoid the construction of enterprises with significant emissions of harmful substances on sites where long-term stagnation of impurities can occur when weak winds and temperature inversions are combined (for example, in deep basins, in areas of frequent fog formation, in particular in areas with severe winters below hydroelectric dams, as well as in areas where smog may occur).[...]

In some cases, the determination of gross production is carried out according to the daily curve of the CO2 level in the cenosis. In an oak-pine forest, for example, the air drops some nights as a result of a temperature inversion (temperature increases from the soil up into the canopy). In this case, CO2 released during breathing accumulates below the inversion layer and its amount can be measured. By summarizing the results of studying the distribution of CO2 depending on the environmental temperature in different seasons of the year, it is possible to obtain approximate estimates of the respiration rate of the entire community as a whole. Thus, the cost of respiration for the oak-pine community is 2110 g/m2-year. Measurements in a gas chamber show that plants directly spend 1450 g/m2-year on respiration. The difference between these two figures, equal to 660 g/m2-year, is the result of the respiration of animals and saprobes.[...]

The distribution of technogenic impurities depends on the power and location of the sources, the height of the pipes, the composition and temperature of the exhaust gases and, of course, on meteorological conditions. Calm, fog, and temperature inversion sharply slow down the dispersion of emissions and can cause excessive local air pollution and the formation of a gas-smoke “cap” over the city. This is how the catastrophic London smog arose at the end of 1951, when 3.5 thousand people died in two weeks from a sharp exacerbation of pulmonary and heart diseases and direct poisoning. Smog in the Ruhr region at the end of 1962 killed 156 people in three days. There are known cases of very serious smog phenomena in Mexico City, Los Angeles and many other large cities.[...]

Mountain valleys oriented along the direction of prevailing winds are characterized by increased average wind speed, especially with large horizontal atmospheric pressure gradients. Under such conditions, temperature inversions occur less frequently. In addition, if temperature inversions occur simultaneously with moderate and strong winds, then their effect on the dissipative properties of the atmosphere is small. The conditions for the dispersion of impurities in valleys of this type are more favorable than in valleys where the wind lash is weaker than in flat conditions. [...]

Conditions conducive to the formation of photochemical fog at high levels of atmospheric air pollution with reactive organic compounds and nitrogen oxides are an abundance of solar radiation, temperature inversions and low wind speeds.[...]

A typical example of the acute provoking influence of atmospheric pollution is the cases of toxic fogs that occurred at different times in cities on different continents of the world. Toxic fogs appear during periods of temperature inversions with low wind activity, i.e., in conditions conducive to the accumulation of industrial emissions in the surface layer of the atmosphere. During periods of toxic fog, an increase in pollution was recorded, the more significant the longer the conditions for air stagnation persisted (3-5 days). During periods of toxic fog, the mortality rate of people suffering from chronic cardiovascular and pulmonary diseases increased, and exacerbations of these diseases and the emergence of new cases were recorded among those who sought medical help. Outbreaks of bronchial asthma have been described in a number of populated areas when specific contaminants appear. It can be assumed that acute cases of allergic diseases will occur when air is polluted with biological products such as protein dust, yeast, mold and their waste products. An example of the acute effects of air pollution are cases of photochemical fog due to a combination of factors: vehicle emissions, high humidity, calm weather, intense ultraviolet radiation. Clinical manifestations: irritation of the mucous membranes of the eyes, nose, upper respiratory tract.[...]

Thus, nowhere on the territory of the USSR are such unfavorable meteorological conditions created for the transfer and dispersion of emissions from low emission sources as on the territory of the Baikal-Amur Mainline. Calculations show that due to the high frequency of stagnant conditions in a large layer of the atmosphere and powerful temperature inversions with the same emission parameters, the level of air pollution in the cities and towns of BAM can be 2-3 times higher than in the European territory of the country. In this regard, protecting the air basin from pollution of the newly developed territory adjacent to the BAM is especially important.[...]

Probably the most notorious smog area in the world is Los Angeles. There are plenty of chimneys in this city. In addition, there is a huge number of cars. Together with these generous suppliers of smoke and soot, both elements of smog formation that played such an important role in Donora act: temperature inversions and the mountainous nature of the terrain. [...]

The Norilsk industrial region is located in the extreme northwestern part of the Central Siberian Plateau, due to which it is characterized by the presence of a sharply continental Arctic climate (average annual temperature -9.9°C, average July temperature +14.0°C, and January -27.6°C . Winter in Norilsk lasts about 9 months. Long winters - little snow, frequent air temperature inversions. During periods of cyclonic activity, in a snowstorm, wind speeds can reach 40 m/s. Summer begins after July 5-10 and lasts two to three weeks ; the rest falls in spring and autumn. Up to 1000-1100 mm of precipitation falls on the plateau, in depressions - a little less than half of this amount. About 2/3 of precipitation is rain. This is not bad at all, because acid precipitation is less damaging to vegetation than dry precipitation sulfur.[...]

Industrial enterprises, urban transport and heat-generating installations are the cause of the occurrence (mainly in cities) of smog: unacceptable pollution of the outdoor air environment inhabited by humans due to the release of harmful substances into it by the indicated sources under unfavorable weather conditions (lack of wind, temperature inversion, etc.). [...]

The next stage of research into the properties of the DBC coenzyme was the study of the circular dichroism (CD) curves of the coenzyme and its analogues. Although a clear interpretation of CD curves does not yet exist, examination of the CD spectra of various corrin compounds shows that there is a parallel between CD curves and ultraviolet spectra. Particularly important was the property of CD curves to undergo inversion upon substitution of the cross-axial ligands X and Y, while such substitution has little effect on the ultraviolet spectra. The results we obtained when studying the CD curves of 5-deoxynucleoside analogues of the DBA coenzyme turned out to be interesting. In this case, it turned out that at 300-600 nm the curves of the CD coenzyme and analogues are almost identical, and in the region of 230-300 nm in some cases a large difference is observed. These results certainly need to be taken into account in a comparative study of CD curves of B-dependent enzymes. [...]

In table Table 5.3 provides estimates of the amounts of five major air pollutants emitted into the atmosphere over the continental United States in selected years. About 60% of pollutants are brought from other areas, industry provides 20%, power plants - 12%, heating - 8%. While the greatest direct threat to human health comes from pollutants that accumulate in high concentrations during temperature inversions over cities such as Tokyo, Los Angeles and New York (layers of warm air prevent pollutants from rising and dissipating), their impact on a national scale and the whole world also cannot be neglected. As can be seen from table. 5.3, the amount of pollutants peaked in the early 70s, and by the end of the decade it had fallen by about 5%, with the amount of suspended particles falling by 43%. Air quality in the United States is improving: A 1980 report from the Council on Environmental Quality noted that in 23 cities, the number of "unhealthy" or hazardous days (as measured by a fairly arbitrary clean air standard) fell by 18% from 1974 to 1978. It appears that fuel and energy conservation measures and the installation of federally mandated air pollution control devices have at least stopped the increase in air pollution. A similar stop in the growth of air pollution has been noted in Europe.[...]

The main reason for the formation of photochemical fog is severe pollution of urban air with gas emissions from chemical industry and transport enterprises and mainly from vehicle exhaust gases. For every kilometer of travel, a passenger car emits about 10 g of nitrogen oxide. In Los Angeles, where over 4 million cars have accumulated, they emit about 1 thousand tons of this gas per day into the air. In addition, temperature inversions are frequent here (up to 260 days a year), contributing to air stagnation over the city. Photochemical fog occurs in polluted air as a result of photochemical reactions occurring under the influence of short-wave (ultraviolet) solar radiation on gas emissions. Many of these reactions create substances that are significantly more toxic than the original ones. The main components of photochemical smog are photooxidants (ozone, organic peroxides, nitrates, nitrites, peroxylacetyl nitrate), nitrogen oxides, carbon monoxide and dioxide, hydrocarbons, aldehydes, ketones, phenols, methanol, etc. These substances are always present in the air in smaller quantities large cities, in photochemical smog their concentration often far exceeds the maximum permissible standards.[...]

Hydrocarbons, sulfur dioxide, nitrogen oxide, hydrogen sulfide and other gaseous substances entering the atmosphere are removed from it relatively quickly. Hydrocarbons are removed from the atmosphere due to the dissolution of seas and oceans in water and subsequent photochemical and biological processes occurring with the participation of microorganisms in water and soil. Sulfur dioxide and hydrogen sulfide, oxidizing to sulfates, are deposited on the surface of the earth. Possessing acidic properties, they are sources of corrosion of various structures made of concrete and metal; they also destroy products made of plastics, artificial fibers, fabrics, leather, etc. A significant amount of sulfur dioxide is absorbed by vegetation and dissolved in the water of the seas and oceans. Carbon monoxide is oxidized to carbon dioxide, which is intensively absorbed by vegetation in the process of photochemical synthesis. Nitrogen oxides are removed due to reduction and oxidation reactions (with strong solar radiation and temperature inversion, they form smog that is dangerous for breathing).

Inversion means an anomalous change in some parameter in the atmosphere with increasing altitude. Most often this refers to temperature inversion, that is, an increase in temperature with height in a certain layer of the atmosphere instead of the usual decrease.

Temperature inversion prevents vertical air movements and contributes to the formation of haze, fog, smog, clouds, and mirages.

Causes and mechanisms of inversion. Under certain conditions, the normal vertical temperature gradient changes in such a way that cooler air ends up near the Earth's surface. This can happen, for example, when a warm, less dense air mass moves over a cold, more dense layer. This type of inversion occurs near warm fronts, as well as in areas of oceanic upwelling, such as off the coast of California. With sufficient moisture in the cooler layer, fog formation under the inversion “lid” is typical. On a clear, quiet night during an anticyclone, cold air can descend down the slopes and collect in the valleys, where the resulting air temperature will be lower than 100 or 200 m higher. Above the cold layer there will be warmer air, which will likely form a cloud or light fog. Temperature inversion is clearly demonstrated by the example of smoke from a fire. The smoke will rise vertically and then bend horizontally when it reaches the “inversion layer.” If this situation is created on a large scale, dust and dirt (smog) rising into the atmosphere remain there and, when accumulated, lead to serious pollution.

Inversion of descent

A temperature inversion can occur in the free atmosphere when a broad layer of air sinks and heats up due to adiabatic compression, which is usually associated with subtropical high pressure areas. Turbulence can gradually lift the inversion layer to a greater height and “puncture” it, resulting in the formation of thunderstorms and even (under certain circumstances) tropical cyclones.

How are the values ​​of the temperature gradient in the troposphere related to the stability of the atmosphere?

The stability of the atmosphere is manifested in the absence of significant vertical movements and mixing in it. Then download substances emitted into the atmosphere near the earth's surface will be retained there. Fortunately, air mixing in the lower atmosphere is facilitated. There are many factors, one of which is temperature gradient. The intensity of thermal mixing is determined by comparing the temperature gradient actually observed in the environment. environment, with an adiabatic vertical temperature gradient (see figure).

When the temp. hail in surroundings environment is greater than G (dry adiab.vertik.grad-t), the atmosphere is superadiabatic. Consider point A in Fig. 5.1.a. If the volume of air with temperature, resp. point A, is transferred quickly upward, its final state may be described by point B on the superadiab.gr straight line. In this comp. its temperature T(1) is higher than the real ambient temperature T(2) at point B. Therefore, the volume of air under consideration will have a lower density than the surrounding environment. air, and the tendency to continue to move upward. If this element. the volume from t.A will start randomly. move down, it will compress adiabatically at a temperature in etc. that is lower than T (ambient air) in i.e. Possessing, therefore, a higher density, the air will continue to move downwards. Thus, an atmosphere characterized by superhadiab. temperature range is unstable. When the ambient air temperature is approximately equal to superadiab. vertical (Fig. 5.1.b), the stability of the atmosphere is called indifferent: if vertical occurs. movement of air volume, then its temperature. the same as the surrounding air, there is no tendency to move further. If temp. The degree of ambient air is less than G, then the atmosphere is subadiabatic (Fig. 5.1.c). Similarly with the previous conclusion, it can be shown that it is stable, because accidentally moved the volume of air will tend to return to its original value. position.